
// Copyright (c) 2010-2021 niXman (github dot nixman at pm dot me). All
// rights reserved.
//
// This file is part of YAS(https://github.com/niXman/yas) project.
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
//
//
// Boost Software License - Version 1.0 - August 17th, 2003
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
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#ifndef __yas__detail__tools__ctmap_hpp
#define __yas__detail__tools__ctmap_hpp

#include <tuple>
#include <cstdint>

namespace yas {
namespace detail {

/***************************************************************************/

template<typename K, typename V>
struct pair {
    K key;
    V val;
};

using optional_t = pair<bool, std::uint8_t>;

template<typename>
struct ctmap;

template<typename... KVI>
struct ctmap<std::tuple<KVI...>> {
    optional_t find(std::uint32_t k) const {
        auto beg = &kvis[0];
        auto end = &kvis[sizeof...(KVI)];
        std::size_t count = sizeof...(KVI);

        while ( count > 0 ) {
            if ( (beg+count/2)->key < k ) {
                beg = beg+count/2+1;
                count -= count/2+1;
            } else {
                count = count/2;
            }
        }

        return {(beg != end && beg->key == k), beg->val};
    }

    static constexpr pair<std::uint32_t, std::uint8_t> kvis[] = {
        {KVI::first_type::value, KVI::second_type::value}...
    };
};
template<typename... KVI>
constexpr pair<std::uint32_t, std::uint8_t> ctmap<std::tuple<KVI...>>::kvis[];

template<typename KVI>
struct ctmap<std::tuple<KVI>> {
    optional_t find(std::uint32_t k) const {
        return {KVI::first_type::value == k, KVI::second_type::value};
    }
};

template<>
struct ctmap<std::tuple<>> {
    optional_t find(std::uint32_t /*k*/) const {
        return {false, 0};
    }
};

/***************************************************************************/

} // ns detail
} // ns yas

#endif // __yas__detail__tools__ctmap_hpp
